Patent GB-535741-A (GB)
Title: Improvements in or relating to systems for transmitting electric signals
IPC: H04L1/14
Filed: 1939-10-18
Abstract: 535,741. Transmitting and reproducing data electrically at a distance. BRITISH TABULATING MACHINE CO., Ltd. Oct. 18, 1939, No. 28190. Conventiondate, Oct. 19, 1938. [Class 40 (iii)] Apparatus for transmitting electric signals between a transmitter station A, Figs. 1 and 1a, and a receiver station B, Figs. 2 and 2a, comprises means (wireless transmitter 43, Fig. 1) at station A to send an electric signal representing a character to station B, recording mechanism at B controlled by a signal from A to record (punch) the related character, reading means 22 at B to read the recorded character automatically, means (wireless transmitter 125, Fig. 2a) at station B operable by the reading means to send to station A an electric signal representing a recorded character that has been read, and means (printing magnets S<SP>1</SP>1 &c.) at A controlled by the signal received from B to convert that signal to a visible character. In this way it may be checked not only that the correct signal was received at B but that the record card was correctly punched at B according to that signal. Station A consists of transmitting means Fig. 1 and receiving means Fig. 1a ; with printing means S1, S2, S3 and S<SP>1</SP>1, S<SP>1</SP>2, S<SP>1</SP>3. Station B consists of receiving means Fig. 2 with punching and printing means and transmitter means Fig. 2a which, after the card holes are read by contacts 22, send impulses to station A. The apparatus, is shown for transmitting three characters-keys 11, 12, 13, Fig. 1-but may be enlarged for more. To distinguish the characters in transmission, they are represented by a different number of impulses, e.g. the numeral " 2 " is represented by two impulses. When the key 12, Fig. 1, is closed, " 2 " is printed by a typewriter solenoid S2 and the contacts to the left of the energized relay 32 co-act with commutator 20 and relays 30, 38 to emit two impulses from wireless transmitter 43. These two impulses are picked up by wireless receiver 50, Fig. 2, and energize first relay R1 and then relay R2 (relay R1 being simultaneously again de-energized) to cause printing of numeral " 2 " by the related printer magnet 62 and punching of " 2 " in the first column of the record card by related punch selector magnet 72 and a common punch actuator magnet 75. The punching mechanism is of the column-by-column escapement-controlledkind set out in Specification 362,529, [Group VIII]. The appropriate contacts in Fig. 2 are delayed by dashpots so that there is time to receive the maximum number of impulses which may represent a single signal (seven in the present instance), the last impulse of the signal being the effective impulse. Energization of punch activator magnet 75 causes the card to escape one column so that the next column is beneath the punches. Another key is then depressed at station A to cause printing and punching of the next character at station B. When the second column is at the punches the first column is at reading balls 22, Fig. 2a, so that the justpunched first column is read and relays 78 (for the numeral " 2 ") and then 88 are energized to store the character read in the first tier 87 ... 90 of a storage device. For this, brushes 84 bridge a strip 82 and a spot 85. Brushes 84 are carried on the card carriages so that as the card next escapes to the third column, brushes 84 move to spot 86 to store the reading of the second-punched column into tier 96 ... 99 and so on. After punching of the card has been completed, a verifying key 16, Fig. 1, is depressed and a signal of six impulses is passed from transmitter 43 to receiver 50 to energize relay R6, Fig. 2. This energizes solenoid 102 and then relay 103 of which latter, contacts 103b, Fig. 2a, close and co-act with commutator 24 to cause a readout, one by one, of the characters stored in devices 87-90, 96-99, &c. The read-out is effected by commutators 115 and 24 to emit the appropriate number of impulses for each signal through wireless transmitter 125. As each signal is received seriatim by the receiving apparatus of station A, Fig. 1a, its impulses are received by relays R1, R2 &c. in a similar manner to the action of relays R1, R2 &c. Fig. 2 and cause energization of the print magnets S<SP>1</SP>1, S<SP>1</SP>2, &c. to record the signals emitted from station B. The operator then checks the printed record just made with the printed data which was originally transmitted over keys 11, 12, and 13. If there be agreement the card feed key 15, Fig. 1, is depressed and printing and punching are effected for a new record at station B. For disagreement an adjust key 17 is closed and causes a green or red signal to light at station B. Means are provided for automatically or manually adjusting the above-mentioned dashpot control of certain contacts until the delay action is just sufficient to permit the reception of the maximum number of impulses which constitute one signal.